The invention relates to a device for manufacturing a pre-assembly for a tyre, which device is provided with a building drum for receiving the pre-assembly, with an inner liner stock roll for containing an inner liner, with a first side wall stock roll for containing a first side wall and a second side wall stock roll for containing a second side wall, with a joining device for joining the inner liner and the side walls together into a pre-assembly, wherein in the pre-assembly the first and second side walls are situated on either side of the inner liner, which joining device is provided with a cutting device for cutting the pre-assembly to length and with a supply conveyor for conveying the cut pre-assembly to the building drum.
Such a device for manufacturing a pre-assembly for a tyre is among others known from EP-A2-0 744 278. In said device the pre-assembly is cut to a length corresponding with the circumference of the building drum, wherein it is desirable that the leading end of the cut pre-assembly and the trailing end of the cut pre-assembly come to abut each other fittingly without a gap or overlap in order for a proper splice to be formed between them. As the inner liner and the side walls are made of different materials, and due to winding the materials onto the stock rolls different tensions are present in the materials, differences in length often occur after cutting the material. As a result it often happens that the leading and the trailing end lie at different distances from each other on the building drum. An operator then ensures manually that the leading and trailing end come to abut each other correctly. Not only does said manual correction take time, it cannot always take place reproducibly either.